DE102021129937A1 - METHOD, COMPUTER PROGRAM PRODUCT, DRIVING ASSISTANCE SYSTEM AND VEHICLE - Google Patents

Abstract

A method for operating a driver assistance system (110) for a vehicle (300) comprising a vehicle (100) with a trailer (200) coupled to the vehicle (100) is proposed. The driver assistance system (110) is set up to automatically drive the vehicle combination (300). The method comprises the steps: receiving (S1) a target trailer orientation, which includes a target value for an orientation of the trailer (200), receiving (S2) an indicative of an actual articulation angle articulation angle sensor signal, the articulation angle (HA) a Angle between a vehicle longitudinal axis (105) and a trailer longitudinal axis (205), and determining the actual articulation angle as a function of the articulation angle sensor signal received, determining (S3) an actual vehicle orientation in relation to a world coordinate system (KK), determining ( S4) an actual trailer orientation in relation to the world coordinate system (KK) based on the determined actual articulation angle and the determined actual vehicle orientation,determining (S5) a corrective driving maneuver depending on the received target trailer orientation and the determined actual Trailer orientation, the actual trailer orientation being equal to the target trailer orientation after the corrective driving maneuver has been carried out, andcausing (S6) the corrective driving maneuver determined to be carried out.

Description

The present invention relates to a method, a computer program product, a driver assistance system and a vehicle.

For many users who only occasionally drive a vehicle-trailer combination, driving the combination in tight quarters and backing up the combination is a challenge. Especially when reversing, the combination forms a pseudo-stable system, since if the trailer deflects from the direction of travel, the deflection of the trailer increases self-reinforcing without the vehicle adapting the direction of travel. The deflection of the trailer from the direction of travel can also occur suddenly due to small influences, such as different rolling resistance of the trailer wheels.

Driving assistance systems are known which support the user when driving with a car and trailer. Extensive sensor technology and high computing power may be necessary for this in order to determine in real time steering movements of the vehicle that bring the trailer to a previously determined trajectory.

DE 10 2019 007 826 A1 discloses a method for operating a vehicle-trailer combination, in which a trailer is coupled to a towing vehicle by means of a drawbar, with trailer data, including a drawbar length, being determined when the vehicle-trailer combination is being driven, the determined trailer data being stored in the towing vehicle and after a renewed activation of driving operation, the stored trailer data are made available to a trailer assistance system. It is provided that, depending on the stored trailer data, an articulation angle of the trailer relative to the towing vehicle is predicted for a specific driving maneuver and stored as a target articulation angle, and an actual articulation angle is determined during driving when the driving maneuver is carried out and compared with the target articulation angle , wherein a previous change of the trailer is detected during a non-driving operation of the vehicle-trailer combination when the actual articulation angle deviates from the target articulation angle by a predetermined amount.

Against this background, one object of the present invention is to improve the operation of a driver assistance system for a vehicle combination.

• Empfangen einer Soll-Anhängerorientierung, welche einen Sollwert für eine Orientierung des Anhängers umfasst,
• Empfangen eines für einen Ist-Knickwinkel indikativen Knickwinkel-Sensorsignals, wobei der Knickwinkel ein Winkel zwischen einer Fahrzeuglängsachse und einer Anhängerlängsachse ist, und Ermitteln des Ist-Knickwinkels in Abhängigkeit des empfangenen Knickwinkel-Sensorsignals,
• Ermitteln einer Ist-Fahrzeugorientierung in Bezug auf ein Welt-Koordinatensystem,
• Ermitteln einer Ist-Anhängerorientierung in Bezug auf das Welt-Koordinatensystem auf Basis des ermittelten Ist-Knickwinkels und der ermittelten Ist-Fahrzeugorientierung,
• Ermitteln eines Korrektur-Fahrmanövers in Abhängigkeit der empfangenen Soll-Anhängerorientierung und der ermittelten Ist-Anhängerorientierung, wobei nach Durchführung des Korrektur-Fahrmanövers die Ist-Anhängerorientierung gleich der Soll-Anhängerorientierung ist, und
• Veranlassen einer Durchführung des ermittelten Korrektur-Fahrmanövers.

According to a first aspect, a method for operating a driver assistance system for a vehicle combination comprising a vehicle with a trailer coupled to the vehicle is proposed. The driver assistance system is set up to drive the vehicle combination automatically. The procedure includes the steps:

• receiving a target trailer orientation, which includes a target value for an orientation of the trailer,
• Receiving an articulation angle sensor signal indicative of an actual articulation angle, the articulation angle being an angle between a vehicle longitudinal axis and a trailer longitudinal axis, and determining the actual articulation angle as a function of the received articulation angle sensor signal,
• determining an actual vehicle orientation with respect to a world coordinate system,
• determining an actual trailer orientation in relation to the world coordinate system based on the determined actual articulation angle and the determined actual vehicle orientation,
• Determining a corrective driving maneuver as a function of the received target trailer orientation and the determined actual trailer orientation, the actual trailer orientation being equal to the target trailer orientation after the corrective driving maneuver has been carried out, and
• Initiating the determined corrective driving maneuver to be carried out.

This method has the advantage that it enables the vehicle combination to travel in a stable manner without the need for complex calculations of trajectories and complex control and regulation processes for guiding the vehicle combination according to a determined trajectory. Instead, only the target orientation of the trailer is set and kept constant.

It can also be said that instead of an exact path control, in which the vehicle with the trailer is controlled in such a way that the trailer follows a specific trajectory as precisely as possible, the orientation of the trailer is controlled. In the special case of straight reversing, this can lead to a slight parallel offset of the car-trailer combination in relation to a starting position, but a less complex sensor system and less computing power are advantageously required. In addition, the journey can be carried out with fewer corrective interventions, which is why the journey can be carried out more quickly.

In the present case, the fact that the driver assistance system is set up to drive the vehicle combination automatically means that the Driving assistance system, for example, has a control unit that is set up to control the vehicle systems relevant to driving the vehicle, such as engine, clutch, transmission, brake, steering and the like, in particular with a trailer coupled to the vehicle. One can also say that the driver assistance system is set up for semi-autonomous or fully autonomous driving of the vehicle with a trailer coupled to it.

The vehicle is, for example, a passenger car or a truck. The vehicle preferably includes a number of sensor units that are set up to detect the driving state of the vehicle and to detect an environment of the vehicle. Examples of such sensor units of the vehicle are image recording devices such as a camera, radar (radio detection and ranging) or also a lidar (engl. light detection and ranging), ultrasonic sensors, location sensors, wheel angle sensors and/or wheel speed sensors. The sensor units are each set up to output a sensor signal, for example to the driver assistance system, which carries out the partially autonomous or fully autonomous driving as a function of the detected sensor signals. The vehicle has, for example, two axles, with preferably only one of the axles carrying steerable wheels, for example the vehicle has only front-axle steering. The proposed method can also be carried out with a vehicle which, for example, has rear-axle steering in addition to front-axle steering. This makes the kinematics of the vehicle more complex, but there are also more diverse possibilities for the corrective driving maneuver in order to bring the trailer into the target orientation.

The trailer is in particular a trailer without its own drive, which means that it is pulled by the vehicle. The trailer can have one or two or more axles. The trailer preferably has no steerable or swiveling wheels. If the trailer has steerable or swiveling wheels, a wheel angle sensor signal is preferably transmitted from the trailer to the driver assistance system. A steerable wheel is understood here to mean that the wheel angle can be controlled. A swiveling wheel is understood to mean, for example, that the wheel angle is variable but not controllable.

The target trailer orientation is specifically related to the world coordinate system. The world coordinate system is, for example, a stationary coordinate system that is defined, for example, by coordinates with respect to the earth's surface, such as GPS coordinates. The world coordinate system thus offers the possibility of specifying an absolute orientation for every object in the world. In this case, the orientation is specified, for example, as an angle, with the angle being measured between a zero orientation in the world coordinate system and a predetermined orientation axis of the respective object. The predetermined orientation axis for the trailer and the vehicle is, for example, the respective longitudinal axis. The orientation can be specified, for example, as an angle between 0° and 360°. Alternatively, the orientation can also be specified as an angle between 180° and -180°, positive values denoting a deviation in a first direction and negative values denoting a deviation in a second direction opposite the first direction.

The articulation angle is the angle between the longitudinal axis of the vehicle and the longitudinal axis of the trailer and thus describes the relative orientation between the vehicle and the trailer. The actual articulation angle relates to the current relative orientation between the vehicle and the trailer at a current point in time.

After the actual vehicle orientation, which is the current vehicle orientation at a current point in time, has been determined, the current actual trailer orientation can be determined on the basis of the determined actual articulation angle and the determined actual vehicle orientation.

A difference between the target trailer orientation and the actual trailer orientation can be compensated for by a suitable corrective driving maneuver that is determined accordingly. After the corrective driving maneuver has been carried out, the actual trailer orientation is equal to the target trailer orientation.

Each of the target trailer orientation, the actual trailer orientation, and the actual vehicle orientation is an absolute orientation with respect to the world coordinate system.

The driver assistance system initiates the corrective driving maneuver determined in this way.

With the proposed method, it is possible to carry out a stable journey with an arbitrarily selectable target trailer orientation. This is particularly advantageous for reversing with the car and trailer combination, since the car and trailer combination does not form a stable system in itself.

The target trailer orientation can vary in particular over time during a journey. In particular, the target trailer orientation in Depending on a route driven (distance covered) and/or depending on an absolute position of the vehicle combination in the world coordinate system. This makes it possible to drive a predetermined or determined trajectory with the combination, with the trailer orientation being used as a control variable while driving.

• Empfangen eines Soll-Knickwinkels, und
• Ermitteln der Soll-Anhängerorientierung in Abhängigkeit des empfangenen Soll-Knickwinkels und der Ist-Fahrzeugorientierung.

According to one embodiment of the method, this further comprises:

• receiving a target articulation angle, and
• Determining the target trailer orientation as a function of the received target articulation angle and the actual vehicle orientation.

In this embodiment, the target articulation angle is specified, which is particularly advantageous in the case of manual operation by a user, since the relative orientation of the trailer to the vehicle, which is given by the articulation angle, can be easily estimated from the user's point of view.

If the target articulation angle = 0° is selected, the result is straight-ahead driving. If the desired articulation angle ≠ 0° is selected, the result is a journey on an arc of a circle, with the radius of the arc of a circle depending on the articulation angle selected and the geometry of the vehicle combination.

• Empfangen eines Orientierungs-Sensorsignals, welches indikativ für die Ist-Orientierung des Fahrzeugs ist, und
• Ermitteln der Ist-Fahrzeugorientierung in Abhängigkeit des empfangenen Orientierungs-Sensorsignals.

According to a further embodiment of the method, this also includes:

• receiving an orientation sensor signal indicative of the actual orientation of the vehicle, and
• Determining the actual vehicle orientation as a function of the received orientation sensor signal.

According to a further embodiment of the method, the orientation sensor signal includes a measured value that includes a steering angle, a steering angle curve, a wheel speed, a wheel speed curve, a wheel angle and/or a wheel angle curve of the vehicle.

The orientation of the vehicle in the world coordinate system can be determined at any time on the basis of the orientation sensor signal by following the movements of the vehicle while driving. One can also say that the actual vehicle orientation is tracked using odometry in the world coordinate system.

It should be noted that the world coordinate system is not necessarily a universal world coordinate system, but can be a subjective world coordinate system defined by the driver assistance system. For example, at the start of the journey, the world coordinate system is defined in such a way that the vehicle is located at the origin of the world coordinate system and the vehicle orientation is equal to the zero orientation of the world coordinate system.

According to a further embodiment of the method, the articulation angle sensor signal includes an optical sensor signal, an ultrasonic sensor signal, and/or a rotation angle sensor signal.

The optical sensor signal is, for example, a camera image from a reversing camera or a surround view camera (also known as a bird's eye view). The articulation angle can be determined by measuring on the basis of such a camera image. The optical sensor signal can also include a lidar signal, which includes distances as direct measured values. From this, the kink angle can be determined on the basis of geometric considerations. The same applies to an ultrasonic sensor signal, which includes a distance of a respective ultrasonic sensor from an object, for example from the trailer. The rotation angle sensor signal is recorded, for example, by a sleeve that is located on the trailer hitch. In this case, the angle of rotation corresponds to the bending angle.

• Erfassen eines Ist-Knickwinkels in Abhängigkeit einer Fahrstrecke während einer manuellen Fahrt des Gespanns,
• Zwischenspeichern des erfassten Ist-Knickwinkels als Funktion der Fahrstrecke,
• Ermitteln der Soll-Orientierung des Anhängers als Funktion der Fahrstrecke in Abhängigkeit des zwischengespeicherten Ist-Knickwinkels als Funktion der Fahrstrecke, und
• Veranlassen einer Fahrt entlang der Fahrstrecke in entgegengesetzter Richtung unter Verwendung der ermittelten Soll-Orientierung des Anhängers als Funktion der Fahrstrecke.

According to a further embodiment of the method, this also includes:

• Recording an actual articulation angle as a function of a route while the vehicle is being driven manually,
• Temporary storage of the recorded actual articulation angle as a function of the route,
• Determination of the target orientation of the trailer as a function of the route as a function of the temporarily stored actual articulation angle as a function of the route, and
• Initiating a journey along the route in the opposite direction using the determined target orientation of the trailer as a function of the route.

This embodiment allows the user to automatically reverse a trajectory driven forward.

According to a further embodiment of the method, the corrective driving maneuver is determined on the basis of a kinematic model of the combination.

In particular, the kinematic model includes the geometric dimensions of the vehicle and trailer and thus enables trajectories of the to be determined as a function of the steering angle and articulation angle.

According to another embodiment of the method, the kinematic model of the combination includes a first distance from a yaw point of the vehicle to a coupling point at which the trailer is coupled to the vehicle, and a second distance from the coupling point to a yaw point of the trailer.

• Ermitteln eines ersten Lenkwinkels für das Fahrzeug, so dass sich die Ist-Fahrzeugorientierung bei einer Fahrt gemäß dem ersten Lenkwinkel der Ist-Anhängerorientierung annähert,
• Fahren des Gespanns mit dem ersten Lenkwinkel, bis die Ist-Fahrzeugorientierung über die Ist-Anhängerorientierung hinausschießt, so dass sich die Ist-Anhängerorientierung der Soll-Anhängerorientierung annähert,
• Ermitteln eines zweiten Lenkwinkels für das Fahrzeug, der einen gegenüber dem ersten Lenkwinkel umgekehrten Lenkeinschlag aufweist, und
• Fahren des Gespanns gemäß dem zweiten Lenkwinkel, bis die Ist-Anhängerorientierung gleich der Soll-Anhängerorientierung ist.

According to a further embodiment of the method, the determination and implementation of the corrective driving maneuver includes:

• Determining a first steering angle for the vehicle, so that the actual vehicle orientation approaches the actual trailer orientation when driving according to the first steering angle,
• driving the combination with the first steering angle until the actual vehicle orientation overshoots the actual trailer orientation, so that the actual trailer orientation approaches the target trailer orientation,
• Determining a second steering angle for the vehicle, which has a steering angle that is opposite to the first steering angle, and
• Driving the trailer according to the second steering angle until the actual trailer orientation equals the desired trailer orientation.

When the actual vehicle orientation approaches the actual trailer orientation, the articulation angle becomes smaller at the same time.

The fact that the actual vehicle orientation exceeds the actual trailer orientation at the start of the journey means that the vehicle is steered in such a way that the vehicle orientation is changed further in the same direction after the actual trailer orientation has been reached at the start of the journey . As a result, the articulation angle deflects in the opposite direction, causing the actual trailer orientation to trend back toward the target trailer orientation.

According to a second aspect, a computer program product is proposed which comprises instructions which, when the program is executed by a computer, cause the latter to execute the method according to the first aspect.

A computer program product, such as a computer program means, can be made available or supplied by a server in a network, for example, as a storage medium such as a memory card, USB stick, CD-ROM, DVD, or in the form of a downloadable file. This can be done, for example, in a wireless communication network by transferring a corresponding file with the computer program product or the computer program means.

• eine Empfangseinheit zum Empfangen einer Soll-Anhängerorientierung, welche einen Sollwert für eine Orientierung des Anhängers umfasst, und zum Empfangen eines für einen Ist-Knickwinkel indikativen Knickwinkel-Sensorsignals, wobei der Knickwinkel ein Winkel zwischen einer Fahrzeuglängsachse und einer Anhängerlängsachse ist,
• eine Ermittlungseinheit zum Ermitteln des Ist-Knickwinkels in Abhängigkeit des empfangenen Knickwinkel-Sensorsignals, zum Ermitteln einer Ist-Fahrzeugorientierung in Bezug auf ein Welt-Koordinatensystem, zum Ermitteln einer Ist-Anhängerorientierung in Bezug auf das Welt-Koordinatensystem auf Basis des ermittelten Ist-Knickwinkels und der ermittelten Ist-Fahrzeugorientierung, und zum Ermitteln eines Korrektur-Fahrmanövers in Abhängigkeit der empfangenen Soll-Anhängerorientierung und der ermittelten Ist-Anhängerorientierung, wobei nach Durchführung des Korrektur-Fahrmanövers die Ist-Anhängerorientierung gleich der Soll-Anhängerorientierung ist, und
• eine Steuereinheit zum Veranlassen einer Durchführung des ermittelten Korrektur-Fahrmanövers.

According to a third aspect, a driver assistance system for a vehicle that can be coupled to a trailer is proposed. The driver assistance system is set up for automatically driving a vehicle combination comprising the vehicle with a trailer coupled to the vehicle. The driver assistance system has:

• a receiving unit for receiving a target trailer orientation, which includes a target value for an orientation of the trailer, and for receiving an articulation angle sensor signal indicative of an actual articulation angle, the articulation angle being an angle between a vehicle longitudinal axis and a trailer longitudinal axis,
• a determination unit for determining the actual articulation angle as a function of the received articulation angle sensor signal, for determining an actual vehicle orientation in relation to a world coordinate system, for determining an actual trailer orientation in relation to the world coordinate system on the basis of the actual articulation angle determined and the determined actual vehicle orientation, and for determining a corrective driving maneuver as a function of the received target trailer orientation and the determined actual trailer orientation, the actual trailer orientation being equal to the target trailer orientation after the corrective driving maneuver has been carried out, and
• a control unit for causing the determined corrective driving maneuver to be carried out.

The respective unit of the driver assistance system can be implemented in terms of hardware and/or software. In the case of a hardware implementation, the respective unit can be embodied, for example, as a computer or as a microprocessor. In the case of a software implementation, the respective unit can be designed as a computer program product, as a function, as a routine, as an algorithm, as part of a program code or as an executable object. Furthermore, each of the units mentioned here can also be designed as part of a higher-level control system of the vehicle, such as a central electronic control device and/or an engine control unit (ECU: Engine Control Unit).

This driver assistance system has the same advantages as described for the method according to the first aspect. The embodiments and features described for the proposed method according to the first aspect apply accordingly to the proposed driver assistance system.

According to a fourth aspect, a vehicle with a trailer device for coupling a trailer to the vehicle and with a driver assistance system according to the third aspect is proposed.

The vehicle is, for example, a passenger car or a truck. The vehicle preferably includes a number of sensor units that are set up to detect the driving state of the vehicle and to detect an environment of the vehicle. Examples of such sensor units of the vehicle are image recording devices such as a camera, radar (radio detection and ranging) or also a lidar (engl. light detection and ranging), ultrasonic sensors, location sensors, wheel angle sensors and/or wheel speed sensors. The sensor units are each set up to output a sensor signal, for example to the driver assistance system, which carries out the partially autonomous or fully autonomous driving as a function of the detected sensor signals.

Further possible implementations of the invention also include combinations of features or embodiments described above or below with regard to the exemplary embodiments that are not explicitly mentioned. The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

• 1 zeigt eine schematische Ansicht eines Beispiels für ein Gespann umfassend ein Fahrzeug und einen daran anhängten Anhänger;
• 2 zeigt eine beispielhafte Trajektorie eines Gespanns und zwei Diagramme, wenn auf den Knickwinkel geregelt wird;
• 3 zeigt eine beispielhafte Trajektorie eines Gespanns und zwei Diagramme, wenn auf die Anhängerorientierung geregelt wird;
• 4 zeigt ein schematisches Blockschaltbild eines Ausführungsbeispiels für ein Fahrassistenzsystem; und
• 5 zeigt ein schematisches Blockdiagramm eines Ausführungsbeispiels für ein Verfahren zum Betreiben eines Fahrassistenzsystems.

Further advantageous refinements and aspects of the invention are the subject matter of the dependent claims and of the exemplary embodiments of the invention described below. The invention is explained in more detail below on the basis of preferred embodiments with reference to the enclosed figures.

• 1 shows a schematic view of an example of a combination comprising a vehicle and a trailer attached to it;
• 2 shows an exemplary trajectory of a combination and two diagrams when the articulation angle is controlled;
• 3 shows an exemplary trajectory of a combination and two diagrams when the trailer orientation is controlled;
• 4 shows a schematic block diagram of an exemplary embodiment of a driver assistance system; and
• 5 shows a schematic block diagram of an exemplary embodiment of a method for operating a driver assistance system.

Elements that are the same or have the same function have been provided with the same reference symbols in the figures, unless otherwise stated.

1 shows a schematic view of an example of a combination 300 comprising a vehicle 100 and a trailer 200 attached thereto from a bird's eye view. The vehicle 100 is, for example, a car with a front axle 101 and a rear axle 102, the vehicle 100 having a front axle steering, as indicated by the pivoted wheels of the front axle 101. Vehicle 100 includes a driver assistance system 110, which is set up to drive vehicle combination 300 automatically, and sensor units 120, 130. This is, for example, a reversing camera 120 that captures an image of a rear area of vehicle 100 and transmits it as an optical sensor signal to the Driver assistance system 110 outputs, as well as ultrasonic sensors 130, each of which detects a distance from objects arranged behind vehicle 100 and outputs it to driver assistance system 110 as an ultrasonic sensor signal. Furthermore, the vehicle 100 has a trailer hitch 140 to which the trailer 200 is coupled. The longitudinal axis 105 of the vehicle 100 defines a specific, vehicle-fixed direction, based on which the vehicle orientation and the articulation angle HA can be determined.

In this example, the trailer 200 has only one axle (no reference number). The longitudinal axis 205 of the trailer 200 defines a specific, trailer-fixed direction, based on which the trailer orientation and the articulation angle HA can be determined.

A world coordinate system KK is shown next to the team 300, which in this case is a rectangular coordinate system with two axes x, y. The actual orientation of the vehicle and the trailer can be determined at any time using the world coordinate system KK. A respective orientation can be specified, for example, as an angle in relation to a specific direction in the world coordinate system KK. In the 1 For example, the actual vehicle orientation is parallel to the y-axis, since the vehicle longitudinal axis 105 runs parallel to the y-axis. The actual vehicle orientation is tracked in particular on the basis of odometry data and is always up-to-date. For example, the actual trailer orientation is approximately along a diagonal of the coor dinate systems KK. If the actual articulation angle HA is known, the actual orientation of the trailer can be inferred from the actual orientation of the vehicle, for example by the actual articulation angle being subtracted from the actual orientation of the vehicle (difference formation).

It should be noted that the sensor units 120, 130 in FIG 1 are merely exemplary and other sensor units and/or additional sensor units can also be used and/or a different arrangement of the sensor units 120, 130 is possible.

The driver assistance system 110 is, for example, as shown in FIG 4 explained formed and is set up to the basis of 5 carry out the procedures explained. Furthermore, the driver assistance system 110 is used to carry out the 3 set up the steps explained.

2 shows an exemplary trajectory TR0 of a combination 300 and two diagrams DIAG1, DIAG2. Diagram DIAG1 shows a course of the orientation OR of vehicle 100 and trailer 200 along the illustrated trajectory TR0 and diagram DIAG3 shows the corresponding course of articulation angle HA. The 2 is an example of how automatic reversing of a vehicle combination 300 could proceed if a driver assistance system 110 (see 1 or 4 ) only regulates to a specific articulation angle HA when reversing. This example is for illustrative purposes only and does not form part of the present invention.

In this example, the zero orientation is selected along the x-axis of the world coordinate system KK. Both the vehicle 100 and the trailer 200 have an actual orientation that is parallel to the zero orientation.

For example, the aim of automatic reversing is to reverse straight ahead, which means that the target trailer orientation corresponds to that of the starting position. Initially, vehicle 100 and trailer 200 are aligned parallel to one another, articulation angle HA is 0. Car-trailer combination 300 therefore initially drives straight backwards from position D0. After a short distance, at position D1, the actual trailer orientation OR2 of the trailer 200 deviates spontaneously due to external influences. As a result, the articulation angle HA assumes a positive value. First of all, the articulation angle HA continues to increase due to the kinematics of a vehicle 300 traveling in reverse. If the deviation of the articulation angle HA has been detected, the driver assistance system 110 takes countermeasures with the vehicle 100 accordingly. For this purpose, vehicle 100 is steered in such a way that actual vehicle orientation OR1 assumes the same value as actual trailer orientation OR2. As soon as the actual orientations OR1, OR2 of vehicle 100 and trailer 205 are the same, which is reached at position D2, the articulation angle HA is again the original value of 0, which is why the combination 300 is again driving along a straight line, but no longer in the original direction.

3 shows an exemplary trajectory TR1 of a combination 300 and two diagrams DIAG1, DIAG2. The team 300 is, for example, that of 1 . Diagram DIAG1 shows a course of the orientation OR of vehicle 100 and trailer 200 along the illustrated trajectory TR0 and diagram DIAG3 shows the corresponding course of articulation angle HA. The 3 is an example of how automatic reversing of a vehicle combination 300 could proceed if a driver assistance system 110 (see 1 or 4 ) regulates to a specific target trailer orientation when reversing. This example is part of the present invention.

The initial situation is, for example, based on the 2 described. However, as soon as the actual orientation OR2 of the trailer 200 deviates from the target orientation at position D1 and this is determined, the driver assistance system 110 steers the vehicle 100 in such a way that the actual vehicle orientation OR1 first approaches the actual trailer orientation OR2 and then overshoots (from position D2). With regard to the articulation angle HA, this means that it first increases, then falls back to zero (as soon as the actual vehicle orientation OR1 is equal to the actual trailer orientation OR2) and then becomes negative (if the actual vehicle orientation OR1 is greater than the actual trailer orientation OR2 is). When the actual trailer orientation OR2 approaches the target value again (zero in this example), the driver assistance system 110 steers the vehicle 100 in such a way that the actual vehicle orientation OR1 also comes back to zero and remains so.

Through this corrective driving maneuver, which compared to the driving maneuver 2 has a second phase in which the actual trailer orientation OR2 is brought back again, the result is that the vehicle combination 300 drives somewhat offset from a trajectory extrapolated from the original position, but in the correct direction.

In the diagram DIAG2 of 3 two areas A1, A2 are drawn. This is the integral between the curve of the articulation angle HA and the zero line. If the goal of the journey is to drive straight ahead, instead of a regulation based on the actual orientation and the Target orientation, a control based on these integrals take place. Starting from the same actual orientation OR1, OR2 of vehicle 100 and trailer 200 (the articulation angle HA is therefore 0), the integral is formed with the aim of keeping the value of the integral at 0. In the example, area A1 has a positive value and area A2 has a negative value. If the areas are the same size, ie A1=A2 or A1−A2=0, then the actual trailer orientation OR2 also corresponds to the initial value, which in this case is the target trailer orientation.

Based on 3 a further embodiment of the driver assistance system 110 can be explained. For example, trajectory TR1 is a trajectory driven manually by a user with vehicle 300 . For example, the user has driven the trajectory forward (in the 3 i.e. from right to left). The actual vehicle orientation OR1 and the articulation angle HA were recorded and stored while driving. This occurs in particular as a function of the distance traveled. For example, point curves are stored that correspond to the curves OR1 and HA shown in the diagrams DIAG1, DIAG2. The user would now like to drive backwards with the vehicle combination 300 the same way that he drove forwards. On the basis of the stored data, driver assistance system 110 is able to determine the target orientation for trailer 200 as a function of position and to control the combination accordingly so that the target orientation is achieved in each case. This enables reverse travel along the same trajectory TR1.

4 FIG. 1 shows a schematic block diagram of an exemplary embodiment of a driver assistance system 110 for a vehicle 100 (see FIG 1 - 3 ), which with a trailer 200 (see 1 - 3 ) can be coupled, the driver assistance system 110 for automatically driving a vehicle combination 300 (see 1 - 3 ) comprising the vehicle 100 is set up with a trailer 200 coupled to the vehicle 100 . Driver assistance system 110 has a receiving unit 112 for receiving a target trailer orientation, which includes a target value for an orientation of trailer 200, and for receiving an articulation angle sensor signal indicative of an actual articulation angle. The kink angle HA (see 1 - 3 ) is an angle between a vehicle longitudinal axis 105 (see 1 - 3 ) and a trailer longitudinal axis 205 (see 1 - 3 ). Driver assistance system 110 also has a determination unit 114 for determining the actual articulation angle as a function of the articulation angle sensor signal received, for determining an actual vehicle orientation OR1 (see 2 or 3 ) with respect to a world coordinate system KK (see 1 - 3 ), for determining an actual trailer orientation OR2 (see 2 or 3 ) in relation to the world coordinate system KK based on the determined actual articulation angle and the determined actual vehicle orientation OR1, and for determining a corrective driving maneuver depending on the received target trailer orientation and the determined actual trailer orientation OR2. The aim of the corrective driving maneuver, which is determined by determination unit 114, is for actual trailer orientation OR2 to be equal to the target trailer orientation. Driver assistance system 110 also has a control unit 116 for causing the determined corrective driving maneuver to be carried out.

5 shows a schematic block diagram of an exemplary embodiment of a method for operating a driver assistance system 110 for a vehicle combination 300 (see 1 - 3 ) comprising a vehicle 100 (see 1 - 3 ) with a trailer 200 coupled to the vehicle 100 (see 1 - 3 ), For example, the driver assistance system 110 of 4 . Driver assistance system 110 is set up to drive vehicle combination 300 automatically. In a first step S1, a target trailer orientation, which includes a target value for an orientation of the trailer (200), is received. The target trailer orientation can be received from an input unit via which the user interacts with the driver assistance system 110, and/or from another unit of the driver assistance system 110, the vehicle 100 or a unit external to the vehicle 100, such as a mobile device of the user , to be received. In embodiments, the target trailer orientation may be received from a path planning unit. In a second step S2, an articulation angle sensor signal indicative of an actual articulation angle is received, the articulation angle HA (see 1 - 3 ) an angle between a vehicle longitudinal axis 105 (see 1 - 3 ) and a trailer longitudinal axis 205 (see 1 - 3 ) and the actual articulation angle is determined as a function of the articulation angle sensor signal received. In a third step S3, an actual vehicle orientation OR1 (see 2 or 3 ) with respect to a world coordinate system KK (see 1 - 3 ) determined. In a fourth step S4, an actual trailer orientation OR2 (see 2 or 3 ) is determined in relation to the world coordinate system KK on the basis of the determined actual articulation angle and the determined actual vehicle orientation OR1. In a fifth step S5, a corrective driving maneuver is determined as a function of the received target trailer orientation and the ascertained actual trailer orientation OR2, the actual trailer orientation OR2 being equal to the target trailer orientation after the corrective driving maneuver has been carried out. in one In the sixth step S6, the determined corrective driving maneuver is initiated.

Although the present invention has been described using exemplary embodiments, it can be modified in many ways.

Reference List

100

vehicle

101

front axle

102

rear axle

105

vehicle orientation

110

driver assistance system

112

receiving unit

114

investigation unit

116

control unit

120

sensor unit

130

sensor unit

140

hitch

200

Fan

205

trailer orientation

300

team

A1

Surface

A2

Surface

D

Route

D0

position

D1

position

D2

position

D3

position

DIAG1

diagram

DIAG2

diagram

HA

kink angle

KK

coordinate system

OR1

vehicle orientation

OR2

trailer orientation

S1

process step

S2

process step

S3

process step

S4

process step

S5

process step

S6

process step

TR0

trajectory

TR1

trajectory

x

coordinate axis

y

coordinate axis

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102019007826 A1 [0004]

Claims (12)

A method for operating a driver assistance system (110) for a vehicle combination (300) comprising a vehicle (100) with a trailer (200) coupled to the vehicle (100), the driver assistance system (110) being set up for automatically driving the vehicle combination (300). , the procedure comprising: Receiving (S1) a target trailer orientation, which includes a target value for an orientation of the trailer (200), Receiving (S2) an articulation angle sensor signal indicative of an actual articulation angle, the articulation angle (HA) being an angle between a vehicle longitudinal axis (105) and a trailer longitudinal axis (205), and determining the actual articulation angle as a function of the received articulation angle sensor signal , Determining (S3) an actual vehicle orientation (OR1) in relation to a world coordinate system (KK), Determining (S4) an actual trailer orientation (OR2) in relation to the world coordinate system (KK) on the basis of the determined actual articulation angle and the determined actual vehicle orientation (OR1), Determining (S5) a corrective driving maneuver as a function of the received target trailer orientation and the determined actual trailer orientation (OR2), the actual trailer orientation (OR2) being equal to the target trailer orientation after the corrective driving maneuver has been carried out, and Initiating (S6) implementation of the determined corrective driving maneuver. procedure after claim 1 , characterized by : receiving a target articulation angle, and determining the target trailer orientation as a function of the received target articulation angle and the actual vehicle orientation (OR1). procedure after claim 1 or 2 , characterized by : receiving an orientation sensor signal which is indicative of the actual orientation of the vehicle (100), and determining the actual vehicle orientation (OR1) as a function of the received orientation sensor signal. procedure after claim 3 , characterized in that the orientation sensor signal includes a measured value comprising a steering angle, a steering angle curve, a wheel speed, a wheel speed curve, a wheel angle and / or a wheel angle curve of the vehicle (100). Method according to one of the preceding claims, characterized in that the kink angle sensor signal comprises an optical sensor signal, an ultrasonic sensor signal and/or a rotation angle sensor signal. Method according to one of the preceding claims, characterized by : detecting an actual articulation angle as a function of a route (D) during manual travel of the combination (300), temporarily storing the detected actual articulation angle as a function of the route (D), determining the target Orientation of the trailer (200) as a function of the route (D) as a function of the temporarily stored actual articulation angle as a function of the route (D), and initiating a journey along the route (D) in the opposite direction using the determined target orientation of the trailer (200) as a function of the driving distance (D). Method according to one of the preceding claims, characterized in that the corrective driving maneuver is determined on the basis of a kinematic model of the combination (300). procedure after claim 7 , characterized in that the kinematic model of the combination (300) a first distance from a yaw point of the vehicle (100) to a coupling point at which the trailer (200) is coupled to the vehicle (100), and a second distance from the Includes coupling point to a yaw point of the trailer (200). Method according to one of the preceding claims, characterized in that determining and carrying out the corrective driving maneuver comprises: determining a first steering angle for the vehicle (100), the first steering angle being determined in such a way that the actual vehicle orientation (OR1) is at approaching a trip with the first steering angle of the actual trailer orientation (OR2), driving the combination (300) with the first steering angle until the actual vehicle orientation (OR1) exceeds the actual trailer orientation (OR2) so that the actual trailer orientation (OR2) approaches the target trailer orientation, determining a second steering angle for the vehicle (100), which has a steering angle that is opposite to the first steering angle, and driving the combination (300) with the second steering angle until the actual trailer orientation is equal to the Target trailer orientation is. Computer program product, comprising instructions which, when the program is executed by a computer, cause the latter to carry out the method according to one of Claims 1 - 9 to execute. Driving assistance system (110) for a vehicle (100) that can be coupled to a trailer (200), the driving assistance system (110) for automatically driving a vehicle combination (300) comprising the vehicle (100) with a coupled to the vehicle (100). Trailer (200) is set up, the driver assistance system (110) having: a receiving unit (112) for receiving a target trailer orientation, which includes a target value for an orientation of the trailer (200), and for receiving an indicative of an actual articulation angle articulation angle sensor signal, the articulation angle (HA) being an angle between a vehicle longitudinal axis (105) and a trailer longitudinal axis (205), a determination unit (114) for determining the actual articulation angle as a function of the articulation angle sensor signal received, for determining an actual vehicle orientation (OR1) in relation to a world coordinate system (KK), for determining an actual trailer orientation (OR2) in relation to the world coordinate system (KK) on the basis of the determined actual articulation angle and the determined actual vehicle orientation (OR1), and for determining a corrective driving maneuver as a function of the received target trailer orientation and the determined actual trailer orientation (OR2), with the actual trailer orientation (OR2) being the same as the target trailer orientation after the corrective driving maneuver has been carried out, and a control unit (116 ) to cause the determined corrective driving maneuver to be carried out. Vehicle (100) with a hitch (150) for coupling a trailer (200) to the vehicle (100), and with a driver assistance system (110). claim 11 .

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